Maybe it accidentally got stuck to your ankle or toe while you were making love in an erotic configuration. .
this is the oldest trick in the book...did he call yet?...every guy knows you need to keep something so they come back to get it and you get another fuck
Sounds like you had a good time! Guess you either need to find the earing or work on losing the other one!
my necklace broke one time because it got caught on his sheets, still a good time though. Jewelry and sex don't mix